On Monday, news broke that Trump’s onetime campaign manager, Paul Manafort, had been indicted in connection with Robert Mueller’s investigation into Russian interference in our election. Ever since then, everyone’s been buzzing about just how dangerous Manafort can be to Trump now. However, we also learned that another Trump associate by the name of George Papadopoulos had been arrested over the summer and pleaded guilty to lying to the FBI.

And Papadopoulos may well be more important to this investigation than Manafort, despite the fact that he isn’t that well known. Why? Because contrary to what Sarah H. Sanders tries telling the media, he was a foreign policy adviser on Trump’s campaign who did, in fact, try colluding with the Russians. And it’s his testimony and documents that could bring Trump’s presidency crashing down around him.

Trump allegedly didn’t say yes to collusion, but he didn’t say no, either

One official connected to the campaign, and who reportedly witnessed Papadopoulos’ efforts to get Trump to meet with Russian officials, says that Trump didn’t dismiss the idea of working with Russia when it was brought up. If Papadopoulos can show that’s what actually happened, Trump himself will be in a lot of trouble sooner than expected.

His testimony could well f*ck over Jeff Sessions

During his confirmation hearing back in January, Sessions told Senator Al Franken that he wasn’t aware of any evidence that anyone colluded with Russia. He later walked that back, but Papadopoulos apparently told various foreign policy committee members about his contact with Russia – a committee which Sessions chaired. Now, Sessions can claim that he opposed the collusion that Papadopoulos was trying to set up, but then he opens himself up to a perjury charge. Either way, he’s fucked.

Papadopoulos’ plea agreement says that the Trump campaign knew about the DNC hacks before they happened

It looks like Papadopoulos was meeting with Russians because they claimed to have dirt on Hillary. His contacts go back to before Don Jr., Jared Kushner and Paul Manafort met with a Russian attorney who claimed to have dirt on Hillary. (Don Jr. originally lied, saying that the meeting was about reinstating adoptions between us and Russia, but then released his own emails that proved he’d lied.)

Then the DNC was hacked, and the hack was traced back to Russia. Trump even called on Russia to release Hillary’s missing emails during the RNC convention; a comment that has been analyzed again and again with some dismissing it as a joke and others saying it was evidence of something deeper.

There’s currently no evidence that anything actually came of that June 2016 meeting. However, if Papadopoulos can back up what he said in his plea agreement about the campaign knowing, then it stops being a scandal and becomes active collusion.

The charges against Papadopoulos are directly connected to the campaign

Manafort and Gates have been charged with things like money laundering, failure to register as foreign agents, etc. The key with these two is whether Mueller can get them to roll over on Trump and other highly placed officials in exchange for lesser charges.

Papadopoulos, on the other hand, told the FBI that his Russian contacts weren’t anyone important and that they had nothing to do with Trump, his campaign, or the election. We now know he was in Europe, meeting with Russians and trying arrange meetings between none other than Vladimir Putin and Donald Trump. There’s a direct line back to the campaign there, whereas the charges against Manafort and Gates could be seen as only tangentially related.

Papadopoulos is already a cooperating witness in Mueller’s investigation, and there is no evidence yet that Manafort or Gates have flipped, or will flip. And since everything about Papadopoulos’ arrest has to do with his activities on the campaign, that makes him far more dangerous to Trump right now than Gates and Manafort.